Manufacture of metal drills



UNITED STATES PATENT OFFICE.

FRANCIS H. RICHARDS, OF SPRINGFIELD, MASSACHUSETTS, ASSIGNOR TO- J. D. COX, JR., AND F. F. PRENTISS, BOTH OF CLEVELAND, OHIO.

MANUFACTURE oF METAL DRILLs.

SPECIFICATION forming part of Letters Patent No. 320,967, dated June 30, 1885.

Application filed August 1, 1883. (No model.)

To all whom it may. concern.-

Beit known that I, FRANcIs H. RIcHARDs, of Springfield, county of Hampden, and State of' Massachusetts, have invented new and useful Improvements in the Manufacture of Metal Drills, of which the following is a specification.

This invention relates to the manufacture of that class of' drills in which the lands are relieved or backed off from the cutting-edge io toward the opposite side thereof.

The object of the invention is to furnish a method or process whereby the best quality of such drills, more especially twist-drills, may be produced with the fewest operations and at the vleast cost; and to this end it consists in the improvements hereinafter described and claimed;

In the drawings, Figure I represents a plain cylindrical drill-blank, such as commonly used 2o for making drills. Fig. 2 represents two drillblanks having incipient grooves formed in them-that shown at a being for a straightgroovcd drill, that lat b for a twist-drill. Fig. 3 shows a drill-blank such as described and clailned in my application No. 101,993. Fig. 4 represents the same blank having formed therein the incipient grooves G G. Fig. 5 represents the drill completed, with the exception of pointing, the grooves being here 3o shown finished to their proper form.

Similar characters designate the'same parts in all the views.

By the old method of' manufacturing relieved drills a drill-blank, sneh as shown in Fig. l,

is first turned truly round7 next grooved, as

shown in Fig. 2 or 5, and then the cuttingedges e, Figs. 3, 4, and 5, are relieved by reducing the part C of the land to a lesser di ameter. The drill being thus completed, it is .4o pointed and tempered, and is then ready for use. By my improved method those operations are simplified and the manufacture of the drills facilitated.

In carrying this method into effect I first shape the required quantity of suitable steel into the form of a cylinder having slightlyelevated ridges, (see e e, Fig. 3,) corresponding in number and position to the cutting-edges which it is desired thc completed drill shall have, as shown in Fig. 3. This operation may 5o bev performed by casting the metal into a mold in'the usual manner of making castings, by i forging it, or by other suitable or similar ways. At the same time the blank is so shaped it may have formed therein the incipient groovesGG, Fig. 4. The shaped blank next has the grooves nished to their final form, substantially as shown in Fig. 5, the metal being removed so as to bring the cutting-edges e e in the highest part of the said 6o ridges. The shaped and grooved blank is now tempered, and being properly pointed is a finished drill.

Having thus described my invention, I claim 65 I. The improved method herein described for making relieved drills, consisting in rst shaping the metal into a cylinder having ridges corresponding in number and position to the grooves the drill is to have, and next 7o making the finished grooves so that one side thereof' shall be in the highest part of said ridges, substantially as described.

2. The improved method herein described for making relieved twistdrills, consisting in first shaping the metal into a cylinder having spiral ridges corresponding in number and position to the grooves the drill is to have, and next making the finished grooves so that one side thereof shall be in the highest part of 8o said ridges, substantially as described.

FRANCIS H. RICHARDS.

Vit-nesses:

CHARLES O. PALMER, FRED. J. DOLE. 

